High-Frequency Biomarker Measurements of Troponin, NT-proBNP, and C-Reactive Protein for Prediction of New Coronary Events After Acute Coronary Syndrome

Soluble Suppression of Tumorigenicity-2 Predicts Mortality and Right Heart Failure in Patients With a Left Ventricular Assist Device

BACKGROUND

Soluble suppression of tumorigenicity-2 (sST2) predicts mortality in patients with heart failure. The predictive value of sST2 in patients with a left ventricular assist device remains unknown. Therefore, we studied the relationship between sST2 and outcome after left ventricular assist device implantation.

METHODS AND RESULTS

sST2 levels of patients with a left ventricular assist device implanted between January 2015 and December 2022 were included in this observational study. The median follow-up was 25 months, during which 1573 postoperative sST2 levels were measured in 199 patients, with a median of 29 ng/mL. Survival of patients with normal and elevated preoperative levels was compared using Kaplan-Meier analysis, which did not differ significantly (P=0.22) between both groups. The relationship between postoperative sST2, survival, and right heart failure was evaluated using a joint model, which showed a significant relationship between the absolute sST2 level and mortality, with a hazard ratio (HR) of 1.20 (95% CI, 1.10-1.130; P<0.01) and an HR of 1.22 (95% CI, 1.07-1.39; P=0.01) for right heart failure, both per 10-unit sST2 increase. The sST2 instantaneous change was not predictive for survival or right heart failure (P=0.99 and P=0.94, respectively). Multivariate joint model analysis showed a significant relationship between sST2 with mortality adjusted for NT-proBNP (N-terminal pro-B-type natriuretic peptide), with an HR of 1.19 (95% CI, 1.00-1.42; P=0.05), whereas the HR of right heart failure was not significant (1.22 [95% CI, 0.94-1.59]; P=0.14), both per 10-unit sST2 increase.

CONCLUSIONS

Time-dependent postoperative sST2 predicts all-cause mortality after left ventricular assist device implantation after adjustment for NT-proBNP. Future research is warranted into possible target interventions and the optimal monitoring frequency.

Acute Coronary Syndrome Subphenotypes Based on Repeated Biomarker Measurements in Relation to Long-Term Mortality Risk

BACKGROUND

We aimed to identify patients with subphenotypes of postacute coronary syndrome (ACS) using repeated measurements of high-sensitivity cardiac troponin T, N-terminal pro-B-type natriuretic peptide, high-sensitivity C-reactive protein, and growth differentiation factor 15 in the year after the index admission, and to investigate their association with long-term mortality risk.

METHODS AND RESULTS

BIOMArCS (BIOMarker Study to Identify the Acute Risk of a Coronary Syndrome) was an observational study of patients with ACS, who underwent high-frequency blood sampling for 1 year. Biomarkers were measured in a median of 16 repeated samples per individual. Cluster analysis was performed to identify biomarker-based subphenotypes in 723 patients without a repeat ACS in the first year. Patients with a repeat ACS (N=36) were considered a separate cluster. Differences in all-cause death were evaluated using accelerated failure time models (median follow-up, 9.1 years; 141 deaths). Three biomarker-based clusters were identified: cluster 1 showed low and stable biomarker concentrations, cluster 2 had elevated concentrations that subsequently decreased, and cluster 3 showed persistently elevated concentrations. The temporal biomarker patterns of patients in cluster 3 were similar to those with a repeat ACS during the first year. Clusters 1 and 2 had a similar and favorable long-term mortality risk. Cluster 3 had the highest mortality risk. The adjusted survival time ratio was 0.64 (95% CI, 0.44-0.93; P=0.018) compared with cluster 1, and 0.71 (95% CI, 0.39-1.32; P=0.281) compared with patients with a repeat ACS.

CONCLUSIONS

Patients with subphenotypes of post-ACS with different all-cause mortality risks during long-term follow-up can be identified on the basis of repeatedly measured cardiovascular biomarkers. Patients with persistently elevated biomarkers have the worst outcomes, regardless of whether they experienced a repeat ACS in the first year.

Trajectories of cardiac troponin in the decades before cardiovascular death: a longitudinal cohort study

BACKGROUND

High-sensitivity cardiac troponin testing is a promising tool for cardiovascular risk prediction, but whether serial testing can dynamically predict risk is uncertain. We evaluated the trajectory of cardiac troponin I in the years prior to a cardiovascular event in the general population, and determine whether serial measurements could track risk within individuals.

METHODS

In the Whitehall II cohort, high-sensitivity cardiac troponin I concentrations were measured on three occasions over a 15-year period. Time trajectories of troponin were constructed in those who died from cardiovascular disease compared to those who survived or died from other causes during follow up and these were externally validated in the HUNT Study. A joint model that adjusts for cardiovascular risk factors was used to estimate risk of cardiovascular death using serial troponin measurements.

RESULTS

In 7,293 individuals (mean 58 ± 7 years, 29.4% women) cardiovascular and non-cardiovascular death occurred in 281 (3.9%) and 914 (12.5%) individuals (median follow-up 21.4 years), respectively. Troponin concentrations increased in those dying from cardiovascular disease with a steeper trajectory compared to those surviving or dying from other causes in Whitehall and HUNT (Pinteraction < 0.05 for both). The joint model demonstrated an independent association between temporal evolution of troponin and risk of cardiovascular death (HR per doubling, 1.45, 95% CI,1.33-1.75).

CONCLUSIONS

Cardiac troponin I concentrations increased in those dying from cardiovascular disease compared to those surviving or dying from other causes over the preceding decades. Serial cardiac troponin testing in the general population has potential to track future cardiovascular risk.

Longitudinal profile of circulating endothelial cells in post-acute coronary syndrome patients

IntroductionPatients who have experienced an acute coronary syndrome (ACS) are at risk of a recurrent event, but their level of risk varies. Because of their close temporal relationship with vascular injury, longitudinal measurements of circulating endothelial cells (CECs) carry potential to improve individual risk assessment.MethodsWe conducted an explorative nested case-control study within our multicenter, prospective, observational biomarker study (BIOMArCS) of 844 ACS patients. Following an index ACS, high-frequency blood sampling was performed during 1-year follow-up. CECs were identified using flow cytometric analyses in 15 cases with recurrent event, and 30 matched controls.ResultsCases and controls had a median (25^th-75^thpercentile) age of 64.1 (58.1-75.1) years and 80% were men. During the months preceding the endpoint, the mean (95%CI) CEC concentration in cases was persistently higher than in controls (12.8 [8.2-20.0] versus 10.0 [7.0-14.4] cells/ml), although this difference was non-significant (P = 0.339). In controls, the mean cell concentration was significantly (P = 0.030) lower in post 30-day samples compared to samples collected within one day after index ACS: 10.1 (7.5-13.6) versus 17.0 (10.8-26.6) cells/ml. Similar results were observed for CEC subsets co-expressing CD133 and CD309 (VEGFR-2) or CD106 (VCAM-1).ConclusionDespite their close relation to vascular damage, no increase in cell concentrations were found prior to the occurrence of a secondary adverse cardiac event.

NT-proBNP Levels and Collateral Circulation Status in Patients with Acute Ischemic Stroke

Methods

In this study, 326 hospitalized patients with acute anterior circulation ischemic stroke (AACIS) were included. A comparison of the clinical characteristics of those with and without AF was conducted. The Spearman rank correlation was used for the correlation analysis of plasma NT-proBNP level, regional leptomeningeal collateral (rLMC) score, and computed tomography perfusion (CTP) status in the AF and non-AF groups. An analysis of multivariate linear regression was used to determine how plasma NT-proBNP level, rLMC score, and CTP status influenced the score on the NIHSS.

Results

There was a greater plasma NT-proBNP level in the AF group compared with the non-AF group, an increased CTP volume (including CTP ischemic volume, CTP infarct core volume, and CTP ischemic penumbra volume (P = 0.002)), higher NIHSS score on admission, and lower rLMC score (P < 0.001 for the remaining parameters). A negative correlation exists between plasma NT-proBNP level and rLMC score (r = -0.156, P = 0.022), but a positive correlation exists between plasma NT-proBNP level and both CTP ischemic volume and CTP infarct core volume (r = 0.148, P = 0.003) in the AF group, but not in the non-AF group. Multivariate linear regression analysis demonstrated that NT-proBNP, CTP ischemic penumbra volume, and rLMC score were associated with NIHSS score, and NT-proBNP was positively associated with NIHSS scores (95% confidence interval (CI), 0.000-0.002; P = 0.004) in the AF group, whatever in the unadjusted model or adjusted models, but not in the nonlarge artery atherosclerosis (LAA) group.

Conclusion

In AACIS patients with AF, NT-proBNP level negatively correlated with collateral status, positively with CTP ischemic volume, and positively with NIHSS score.

Biomarker-based risk model to predict cardiovascular events in patients with acute coronary syndromes - Results from BIPass registry

BACKGROUND

Risk models integrating new biomarkers to predict cardiovascular events in acute coronary syndromes (ACS) are lacking. Therefore, we evaluated the prognostic value of biomarkers in addition to clinical predictors and developed a biomarker-based risk model for major adverse cardiovascular events (MACE) within 12 months after hospital admission with ACS.

METHODS

Patients (n = 4407) consecutively enrolled from November, 2017 to October, 2019 in three hospitals of a prospective Chinese registry (BIomarker-based Prognostic Assessment for Patients with Stable Angina and Acute Coronary Syndromes, BIPass) were designated as the risk model development cohort. Validation was performed in 1409 patients enrolled in two independent hospitals. Cox proportional hazards regression analysis was used to generate a risk prediction model and evaluate the incremental prognostic value of each biomarker.

FINDINGS

Over 12 months, 196 patients experienced MACE (5.1%/year). Among twelve candidate biomarkers, N-terminal pro-B-type natriuretic peptide (NT-proBNP) measured at baseline showed the most prognostic capability independent of clinical predictors. The developed BIPass risk model included age, hypertension, previous myocardial infarction, stroke, Killip class, heart rate, and NT-proBNP. It displayed improved discrimination (C-statistic 0.79, 95% CI 0.73-0.85), calibration (GOF = 9.82, p = 0.28) and clinical decision curve in the validation cohort, outperforming the GRACE and TIMI risk scores. Cumulative rates for MACE demonstrated good separation in the BIPass predicted low, intermediate, and high-risk groups.

INTERPRETATION

The BIPass risk model, integrating clinical variables and NT-proBNP, is useful for predicting 12-month MACE in ACS. It effectively identifies a gradient risk of cardiovascular events to aid personalized care.

FUNDING

National Key R&D Program of China (2017YFC0908700, 2020YFC0846600), National S&T Fundamental Resources Investigation Project (2018FY100600, 2018FY100602), Taishan Pandeng Scholar Program of Shandong Province (tspd20181220), Taishan Young Scholar Program of Shandong Province (tsqn20161065, tsqn201812129), Youth Top-Talent Project of National Ten Thousand Talents Plan and Qilu Young Scholar Program.

Persistently elevated levels of sST2 after acute coronary syndrome are associated with recurrent cardiac events

Purpose Higher soluble ST2 (sST2) levels at admission are associated with adverse outcome in acute coronary syndrome (ACS) patients. We studied the dynamics of sST2 over time in post-ACS patients prior to a recurrent ACS or cardiac death.Methods We used the BIOMArCS case-cohort, consisting of 187 patients who underwent serial blood sampling during one year follow-up post-ACS. sST2 was batch-wise quantified after completion of follow-up in a median of 8 (IQR: 5-11) samples per patient. Joint-modelling was used to investigate the association between longitudinally measured sST2 and the endpoint, adjusted for gender, GRACE risk score and history of cardiovascular diseases.Results Median age was 64 years and 79% were men. The 36 endpoint patients had systematically higher sST2 levels than those that remained endpoint free (mean value 29.6 ng/ml versus 33.7 ng/ml, p-value 0.052). The adjusted hazard ratio for the endpoint per standard deviation increase of sST2 was 1.64 (95% confidence interval: 1.09-2.34; p = 0.019) at any time point. We could not identify a steady or sudden increase of sST2 in the run-up to the combined endpoint.Conclusion Asymptomatic post-ACS patients with persistently higher sST2 levels are at higher risk of recurrent ACS or cardiac death during one year follow-up.

The age, NT-proBNP, and Ejection Fraction Score as a Novel Predictor of Clinical Outcomes in CAD Patients After PCI

Background

Previous evidences have been proved that age, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and ejection fraction are tightly associated with the long-term outcomes in patients suffered from coronary artery disease (CAD). Therefore, the present study aimed to assess the prognosis value of age, NT-proBNP, and ejection fraction (ABEF) score in CAD patients who underwent percutaneous coronary intervention (PCI).

Methods

Observational cohort methodology was used in this study which enrolled totally 3561 patients. And the patients were followed up regularly for 37.59 ± 22.24 months. Patients were classed into three groups based on the tertiles of ABEF sore: first tertile (<5.06, n = 831), second tertile (5.06-6.25, n = 839), and third tertile (≥ 6.25, n = 834). The ABEF score was calculated as follows: age (years)/ejection fraction (%) + NT-proBNP (NT-proBNP<177pg/mL was 1, 177≤NT-proBNP≥524pg/mL was 2 and NT-proBNP > 524pg/mL is 3). The association between ABEF score and adverse prognosis, including all-cause death (ACD), cardiac death (CD), major adverse cardiovascular events (MACEs) and major adverse cardiac and cerebrovascular events (MACCEs), in patients who underwent PCI was analyzed.

Results

According to the risk category of ABEF score, the incidences of ACD (P < .001), CD (P < .001) and MACCEs (P = .021) among the three groups showed significant differences. Multivariate Cox regression analysis suggested that the respective risks of ACD and CD were increased 3.013 folds (hazard risk [HR] = 4.013 [95% confidence interval [CI]: 1.922-8.378], P < .001) and 4.922 folds ([HR] = 5.922 [95% [CI]: 2.253-15.566], P < .001) in the third tertile compared with those in the first tertile. Kaplan-Meier survival analyses showed that the cumulative risks of ACD,CD and MACCEs in patients with the high ABEF score tended to increase.

Conclusion

The present study indicated ABEF score was a novel biomarker suitable for predicting adverse prognosis in patients after PCI, which may be used for early recognition and risk stratification.

Current Knowledge of MicroRNAs (miRNAs) in Acute Coronary Syndrome (ACS): ST-Elevation Myocardial Infarction (STEMI)

Regardless of the newly diagnostic and therapeutic advances, coronary artery disease (CAD) and more explicitly, ST-elevation myocardial infarction (STEMI), remains one of the leading causes of morbidity and mortality worldwide. Thus, early and prompt diagnosis of cardiac dysfunction is pivotal in STEMI patients for a better prognosis and outcome. In recent years, microRNAs (miRNAs) gained attention as potential biomarkers in myocardial infarction (MI) and acute coronary syndromes (ACS), as they have key roles in heart development, various cardiac processes, and act as indicators of cardiac damage. In this review, we describe the current available knowledge about cardiac miRNAs and their functions, and focus mainly on their potential use as novel circulating diagnostic and prognostic biomarkers in STEMI.

Stabilization patterns and variability of hs-CRP, NT-proBNP and ST2 during 1 year after acute coronary syndrome admission: results of the BIOMArCS study

Objectives Details of the biological variability of high-sensitivity C-reactive protein (hs-CRP), N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and ST2 are currently lacking in patients with acute coronary syndrome (ACS) but are crucial knowledge when aiming to use these biomarkers for personalized risk prediction. In the current study, we report post-ACS kinetics and the variability of the hs-CRP, NT-proBNP and ST2. Methods BIOMArCS is a prospective, observational study with high frequency blood sampling during 1 year post-ACS. Using 1507 blood samples from 191 patients that remained free from adverse cardiac events, we investigated post-ACS kinetics of hs-CRP, NT-proBNP and ST2. Biological variability was studied using the samples collected between 6 and 12 months after the index ACS, when patients were considered to have stable coronary artery disease. Results On average, hs-CRP rose peaked at day 2 and rose well above the reference value. ST2 peaked immediately after the ACS but never rose above the reference value. NT-proBNP level rose on average during the first 2 days post-ACS and slowly declined afterwards. The within-subject variation and relative change value (RCV) of ST2 were relatively small (13.8%, RCV 39.7%), while hs-CRP (41.9%, lognormal RCV 206.1/-67.3%) and NT-proBNP (39.0%, lognormal RCV 185.2/-64.9%) showed a considerable variation. Conclusions Variability of hs-CRP and NT-proBNP within asymptomatic and clinically stable post-ACS patients is considerable. In contrast, within-patient variability of ST2 is low. Given the low within-subject variation, ST2 might be the most useful biomarker for personalizing risk prediction in stable post-ACS patients.

Analysis of risk factors for different subtypes of acute coronary syndrome

AIMS

To investigate the different risk factors among different subtypes of patients with acute coronary syndrome (ACS).

METHODS

A total of 296 patients who had ACS were retrospectively enrolled. Blood and echocardiographic indices were assessed within 24 hours after admission. Differences in risk factors and Gensini scores of coronary lesions among three groups were analyzed.

RESULTS

Univariate analysis of risk factors for ACS subtypes showed that age, and levels of fasting plasma glucose, amino-terminal pro-brain natriuretic peptide, and creatine kinase isoenzyme were significantly higher in patients with non-ST-segment elevation myocardial infarction (NSTEMI) than in those with unstable angina pectoris (UAP). Logistic multivariate regression analysis showed that amino-terminal pro-brain natriuretic peptide and the left ventricular ejection fraction (LVEF) were related to ACS subtypes. The left ventricular end-diastolic diameter was an independent risk factor for UAP and ST-segment elevation myocardial infarction (STEMI) subtypes. The severity of coronary stenosis was significantly higher in NSTEMI and STEMI than in UAP. Gensini scores in the STEMI group were positively correlated with D-dimer levels (r = 0.429) and negatively correlated with the LVEF (r = -0.602).

CONCLUSION

Different subtypes of ACS have different risk factors. Our findings may have important guiding significance for ACS subtype risk assessment and clinical treatment.

Advancements in biomarkers for cardiovascular disease: diagnosis, prognosis, and therapy

Biomarkers are essential tools in the practice of cardiology. They assist with diagnosis, prognosis, and guiding therapy in many different cardiovascular diseases. Numerous biomarkers have become strongly associated with different cardiovascular conditions, such as troponin with acute coronary syndrome and natriuretic peptides with heart failure. Even though these biomarkers have been in practice for almost two decades, their uses continue to expand beyond their original roles. Additionally, many new biomarkers have been discovered with increasing utility in cardiovascular disease, including soluble suppression of tumorigenicity 2, galectin 3, and biomarkers of fibrosis, metabolism, and inflammation. How these old and new biomarkers are being expanded into clinical practice is constantly in evolution. This review will highlight some of the recent major advancements in the rapidly evolving field of biomarkers.

Temporal Evolution of Serum Concentrations of High-Sensitivity Cardiac Troponin During 1 Year After Acute Coronary Syndrome Admission

Background

Detailed insights in temporal evolution of high‐sensitivity cardiac troponin following acute coronary syndrome (ACS) are currently missing. We aimed to describe and compare the post‐ACS kinetics of high‐sensitivity cardiac troponin I (hs‐cTnI) and high‐sensitivity cardiac troponin T (hs‐cTnT), and to determine their intra‐ and interindividual variation in clinically stable patients.

Methods and Results

We determined hs‐cTnI (Abbott) and hs‐cTnT (Roche) in 1507 repeated blood samples, derived from 191 patients with ACS (median, 8/patient) who remained free from adverse cardiac events during 1‐year follow‐up. Post‐ACS kinetics were studied by linear mixed‐effect models. Using the samples collected in the 6‐ to 12‐month post‐ACS time frame, patients were then considered to have chronic coronary syndrome. We determined (differences between) the average hs‐cTnI and average hs‐cTnT concentration, and the intra‐ and interindividual variation for both biomarkers. Compared with hs‐cTnT, hs‐cTnI peaked higher (median 3506 ng/L versus 494 ng/L; P<0.001) and was quicker below the biomarker‐specific upper reference limit (16 versus 19 days; P<0.001). In the post–6‐month samples, hs‐cTnI and hs‐cTnT showed modest correlation (r_spearman=0.60), whereas the average hs‐cTnT concentration was 5 times more likely to be above the upper reference limit than hs‐cTnI. The intraindividual variations of hs‐cTnI and hs‐cTnT were 14.0% and 18.1%, while the interindividual variations were 94.1% and 75.9%.

Conclusions

Hs‐cTnI peaked higher after ACS and was quicker below the upper reference limit. In the post–6‐month samples, hs‐cTnI and hs‐cTnT were clearly not interchangeable, and average hs‐cTnT concentrations were much more often above the upper reference limit than hs‐cTnI. For both markers, the within‐patient variation fell largely below beween‐patient variation.

Registration

URL: https://www.trialregister.nl; unique identifiers: NTR1698 and NTR1106.

Differential associations of cardiac troponin T and cardiac troponin I with coronary artery pathology and dynamics in response to short-duration exercise

BACKGROUND

We aimed to assess the associations between cardiac troponin (cTn) T and I concentrations, physical exercise and the presence and severity of angiographic coronary artery disease (CAD) in patients evaluated for suspected chronic coronary syndrome (CCS).

METHODS AND RESULTS

All patients performed an exercise stress test on a bicycle ergometer and underwent invasive coronary angiography with weighted anatomical evaluation using the Gensini score. Blood samples were collected before and after exercise and analysed with high-sensitivity (hs) cTnT and cTnI assays. Of 297 patients (median age 62 (Quartile [Q]1-3 56-69) years, 35% female), 46% were categorized as "severe CAD" (Gensini score ≥ 20). Resting hs-cTnT and hs-cTnI concentrations were detectable in 88% and 100% of patients, with medians of 6 (Q1-3 4-9) ng/L and 1.5 (0.9-2.4) ng/L, respectively. In adjusted normalized linear regression analyses, higher resting concentrations were associated with increasing Gensini score (hs-cTnT: B 0.19, 95% Confidence Interval [CI] [0.09-0.41], p < 0.001; hs-cTnI: B 0.18, [0.06-0.30], p = 0.002). The area under the receiver operating characteristics curve for predicting severe CAD was 0.72 (95% CI [0.66-0.78]) and 0.68 (0.62-0.74) for resting hs-cTnT and hs-cTnI, p = 0.11 for difference. The median (Q1-3) relative increase in hs-cTnT and hs-cTnI concentrations were 5 (0-12) % and 13 (3-27) %, respectively, with no significant associations with CAD severity.

CONCLUSIONS

In patients with suspected CCS, higher hs-cTn concentrations at rest were associated with increasing angiographic severity of CAD, without any significant differences between the troponin isotypes. Post-exercise hs-cTn concentrations did not have discriminatory power for CAD.

Sex differences in uric acid and NT-pro BNP assessments during coronary severity

To investigate the correlation between uric acid (UA) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and coronary artery severity in acute coronary syndrome patients of different sexes.A total of 134 patients with acute coronary syndrome (ACS) were investigated. According to sex, there were 96 cases in male group and 38 cases in female group. According to the number of diseased vessels, the degree of coronary artery lesion was determined and divided into negative group (n = 21), single vessel lesion group (n = 43), double vessel lesion group (n = 38), and 3 vessel lesion group (n = 32).Univariate analysis showed that UA, NT-proBNP was correlated with the severity of ACS (P < .05). UA was an independent risk factor for the severity of coronary artery disease in female group (P < .05), but not in male group (P > .05). There was no significant correlation between NT-proBNP and severity of coronary artery disease in different sex (P > .05).UA was significantly correlated with the severity of coronary heart disease, especially in women, but not in men. The level of NT-proBNP was positively correlated with the severity of coronary artery, but no significant difference was found in different sexes.

Noncoding RNAs versus Protein Biomarkers in Cardiovascular Disease

The development of more sensitive protein biomarker assays results in continuous improvements in detectability, extending the range of clinical applications to the detection of subclinical cardiovascular disease (CVD). However, these efforts have not yet led to improvements in risk assessment compared with existing risk scores. Noncoding RNAs (ncRNAs) have been assessed as biomarkers, and miRNAs have attracted most attention. More recently, other ncRNA classes have been identified, including long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs). Here, we compare emerging ncRNA biomarkers in the cardiovascular field with protein biomarkers for their potential in clinical application, focusing on myocardial injury.

Evolution of renal function and predictive value of serial renal assessments among patients with acute coronary syndrome: BIOMArCS study

BACKGROUND

Impaired renal function predicts mortality in acute coronary syndrome (ACS), but its evolution immediately following index ACS and preceding next ACS has not been described in detail. We aimed to describe this evolution using serial measurements of creatinine, glomerular filtration rate [eGFR_Cr] and cystatin C [CysC].

METHODS

From 844 ACS patients included in the BIOMArCS study, we analysed patient-specific longitudinal marker trajectories from the case-cohort of 187 patients to determine the risk of the endpoint (cardiovascular death or hospitalization for recurrent non-fatal ACS) during 1-year follow-up. Study included only patients with eGFR_Cr ≥ 30 ml/min/1.73 m². Survival analyses were adjusted for GRACE risk score and based on data >30 days after the index ACS (mean of 8 sample per patient).

RESULTS

Mean age was 63 years, 79% were men, 43% had STEMI, and 67% were in eGFR stages 2-3. During hospitalization for index ACS (median [IQR] duration: 5 (3-7) days), CysC levels indicated deterioration of renal function earlier than creatinine did (CysC peaked on day 3, versus day 6 for creatinine), and both stabilized after two weeks. Higher CysC levels, but not creatinine, predicted the endpoint independently of the GRACE score within the first year after index ACS (adjusted HR [95% CI] per 1SD increase: 1.68 [1.03-2.74]).

CONCLUSION

Immediately following index ACS, plasma CysC levels deteriorate earlier than creatinine-based indices do, but neither marker stabilizes during hospitalization but on average two weeks after ACS. Serially measured CysC levels predict mortality or recurrence of ACS during 1-year follow-up independently of patients' GRACE risk score.

Prognostic Value of Troponins in Patients With or Without Coronary Heart Disease: Is it Dependent on Structure and Biology?

Convincing evidence has emerged that cardiac troponins (cTns) T and I are the biochemical gold standard for diagnosing cardiac injury, and may also be used as efficient screening and risk stratification tools, especially when measured with the new high-sensitivity (hs-) immunoassays. In this narrative review, we aim to explore and critically discuss the results of recent epidemiological studies that have attempted to characterise the prognostic value of cTns in patients with or without cardiovascular disease, and then interpret this information according to cTn biology. Overall, all recent studies agree that higher blood levels of cTns reflect the larger risk of cardiovascular events and/or death, both in the general population and in patients with cardiovascular disease. Additional evidence has shown that the clinical information provided by assessment of both cTns molecules is greater compared to that of either protein alone, and this is mostly due to differential metabolism and clearance of cTnI and cTnT after release in the bloodstream. Although it seems likely that the prognostic value of these biomarkers may be higher than that of other conventional cardiovascular risk factors such as cholesterol or C reactive protein, large and reliable cost-effectiveness investigations are needed to define whether cTns-based population screening may be biologically plausible, clinically effective and economically sustainable.

Temporal evolution of myeloperoxidase and galectin 3 during 1 year after acute coronary syndrome admission

Prior studies reported that Myeloperoxidase and Galectin-3, which are biomarkers of coronary plaque vulnerability, are elevated in acute coronary syndrome (ACS) patients. We studied the temporal evolution of these biomarkers early after ACS admission and prior to a recurrent ACS event during 1 year follow-up.

Joint models for longitudinal and time-to-event data in a case-cohort design

Studies with longitudinal measurements are common in clinical research. Particular interest lies in studies where the repeated measurements are used to predict a time‐to‐event outcome, such as mortality, in a dynamic manner. If event rates in a study are low, however, and most information is to be expected from the patients experiencing the study endpoint, it may be more cost efficient to only use a subset of the data. One way of achieving this is by applying a case‐cohort design, which selects all cases and only a random samples of the noncases. In the standard way of analyzing data in a case‐cohort design, the noncases who were not selected are completely excluded from analysis; however, the overrepresentation of the cases will lead to bias. We propose to include survival information of all patients from the cohort in the analysis. We approach the fact that we do not have longitudinal information for a subset of the patients as a missing data problem and argue that the missingness mechanism is missing at random. Hence, results obtained from an appropriate model, such as a joint model, should remain valid. Simulations indicate that our method performs similar to fitting the model on a full cohort, both in terms of parameters estimates and predictions of survival probabilities. Estimating the model on the classical version of the case‐cohort design shows clear bias and worse performance of the predictions. The procedure is further illustrated in data from a biomarker study on acute coronary syndrome patients, BIOMArCS.